diff --git a/openatlas/api/resources/util.py b/openatlas/api/resources/util.py
index f11aa114d..0bd0f7d2c 100644
--- a/openatlas/api/resources/util.py
+++ b/openatlas/api/resources/util.py
@@ -166,16 +166,16 @@ def get_reference_systems(
         links_inverse: list[Link]) -> list[dict[str, Any]]:
     ref = []
     for link_ in links_inverse:
-        if not isinstance(link_.domain, ReferenceSystem) or not link_.type:
-            continue
-        system = g.reference_systems[link_.domain.id]
-        ref.append({
-            'referenceURL': system.website_url,
-            'id': link_.description,
-            'resolverURL': system.resolver_url,
-            'identifier': f"{system.resolver_url or ''}{link_.description}",
-            'type': to_camel_case(g.types[link_.type.id].name),
-            'referenceSystem': system.name})
+        if isinstance(link_.domain, ReferenceSystem) and link_.type:
+            system = g.reference_systems[link_.domain.id]
+            ref.append({
+                'referenceURL': system.website_url,
+                'id': link_.description,
+                'resolverURL': system.resolver_url,
+                'identifier':
+                    f"{system.resolver_url or ''}{link_.description}",
+                'type': to_camel_case(g.types[link_.type.id].name),
+                'referenceSystem': system.name})
     return ref
 
 
diff --git a/openatlas/views/entity_index.py b/openatlas/views/entity_index.py
index f61bca8f2..6ca2cf84f 100644
--- a/openatlas/views/entity_index.py
+++ b/openatlas/views/entity_index.py
@@ -10,7 +10,7 @@
 from openatlas.display.table import Table
 from openatlas.display.util import (
     button, format_date, get_base_table_data, get_file_path, is_authorized,
-    link, manual, required_group, convert_size)
+    link, manual, required_group)
 from openatlas.models.entity import Entity
 from openatlas.models.gis import Gis
 
diff --git a/tests/test_api.py b/tests/test_api.py
index 0e3c208de..6464f7857 100644
--- a/tests/test_api.py
+++ b/tests/test_api.py
@@ -419,6 +419,8 @@ def test_api(self) -> None:
                 self.app.get(
                     url_for('api_03.type_tree', download=True))]:
                 assert bool(rv.get_json()['typeTree'])
+            rv = self.app.get(url_for('api_03.type_tree', count=True))
+            assert rv.get_json() > 0
 
             for rv in [
                 self.app.get(url_for(
@@ -775,52 +777,62 @@ def test_api(self) -> None:
             rv = self.app.get(url_for('api_03.subunits', id_=actor.id))
             assert 'ID is not a valid place' in rv.get_json()['title']
 
-            rv = self.app.get(url_for(
-                'api_03.query',
-                entities=location.id,
-                cidoc_classes='E18',
-                view_classes='artifact',
-                system_classes='person',
-                sort='desc',
-                column='id',
-                download=True,
-                last=place.id))
-            assert 'ID is last entity' in rv.get_json()['title']
-
-            for rv in [
-                self.app.get(url_for('api_03.query', entities=12345)),
-                self.app.get(url_for(
-                    'api_03.cidoc_class', cidoc_class='E68', last=1231)),
-                self.app.get(url_for(
-                    'api_03.view_class',
-                    view_class='place',
-                    search='{"typeName":[{"operator":"equal",'
-                           '"values":["Boundary Mark", "Height", "Dimension"],'
-                           '"logicalOperator":"and"}]}')),
-                self.app.get(url_for(
-                    'api_03.view_class',
-                    view_class='place',
-                    search='{"beginFrom":[{"operator":"lesserThan",'
-                           '"values":["2000-1-1"],'
-                           '"logicalOperator":"or"}]}')),
-
-                self.app.get(url_for(
+            rv = self.app.get(
+                url_for(
                     'api_03.query',
-                    entities=place.id,
+                    entities=location.id,
                     cidoc_classes='E18',
                     view_classes='artifact',
                     system_classes='person',
-                    format='lp',
-                    search='{"entityDescription":[{"operator":"like",'
-                           '"values":["IS", "sam", "FrOdo"],'
-                           '"logicalOperator":"and"}]}'))]:
+                    sort='desc',
+                    column='id',
+                    download=True,
+                    last=place.id))
+            assert 'ID is last entity' in rv.get_json()['title']
+
+            for rv in [
+                self.app.get(url_for('api_03.query', entities=12345)),
+                self.app.get(
+                    url_for(
+                        'api_03.cidoc_class',
+                        cidoc_class='E68',
+                        last=1231)),
+                self.app.get(
+                    url_for(
+                        'api_03.view_class',
+                        view_class='place',
+                        search=
+                            '{"typeName":[{"operator":"equal",'
+                            '"values":["Boundary Mark", "Height", "Dimension"],'
+                            '"logicalOperator":"and"}]}')),
+                self.app.get(
+                    url_for(
+                        'api_03.view_class',
+                        view_class='place',
+                        search=
+                            '{"beginFrom":[{"operator":"lesserThan",'
+                            '"values":["2000-1-1"],'
+                            '"logicalOperator":"or"}]}')),
+                self.app.get(
+                    url_for(
+                        'api_03.query',
+                        entities=place.id,
+                        cidoc_classes='E18',
+                        view_classes='artifact',
+                        system_classes='person',
+                        format='lp',
+                        search=
+                            '{"entityDescription":[{"operator":"like",'
+                            '"values":["IS", "sam", "FrOdo"],'
+                            '"logicalOperator":"and"}]}'))]:
                 rv = rv.get_json()
                 assert 'No entity available' in rv['title']
 
-            rv = self.app.get(url_for(
-                'api_03.query',
-                system_classes='person',
-                type_id=boundary_mark.id))
+            rv = self.app.get(
+                url_for(
+                    'api_03.query',
+                    system_classes='person',
+                    type_id=boundary_mark.id))
             assert 'One entity ID is not a type' in rv.get_json()['title']
 
             rv = self.app.get(
@@ -873,10 +885,11 @@ def test_api(self) -> None:
                        '"logicalOperator":"or"}]}'))
             assert 'Invalid search syntax' in rv.get_json()['title']
 
-            for rv in [
-                self.app.get(url_for('api_03.type_entities', id_=1234)),
-                self.app.get(url_for('api_03.type_entities_all', id_=1234))]:
-                assert 'Entity is not a type' in rv.get_json()['title']
+            rv = self.app.get(url_for('api_03.type_entities', id_=1234))
+            assert 'Entity is not a type' in rv.get_json()['title']
+
+            rv = self.app.get(url_for('api_03.type_entities_all', id_=1234))
+            assert 'Entity is not a type' in rv.get_json()['title']
 
             rv = self.app.get(url_for(
                 'api_03.view_class',